Impact factor on the pretreatment technology for anaerobic fermentation of rice straw

The pretreatment processing method has obvious influence to the degradation of straw when used as the raw material in anaerobic digestion. Rice straw was chosen as raw material in the research. The experiments was carried out on effects of the straw smashing size, the ratio of carbon to nitrogen, the pile of bubbles time and was designed on the basis of quadratic orthogonal regressive rotational combination principle with three factors and five levels. A quadratic equation for biogas yield was built. The optimal processing parameters which obtained according to the analysis of the data are as follows: the smashing size of rice straw is 4∼8 mm, C/N is 40, the pile of bubbles time is 8 d.